This is a high-value 6 Mark definitive stamp issued by the Weimar Republic under the "Numeral Design" series of 1920. Printed in deep blue, it features a large ornate numeral "6" in the center, surrounded by radiating wave patterns and Gothic lettering that reads Deutsches Reich. High-denomination stamps like this were often used on heavier parcels or bulk mail during the early inflationary period in Germany. Collectors value these issues for their intricate engraving, bold design, and connection to Germany’s turbulent economic years leading up to hyperinflation.